Why #Autowired and #Value fields are not injected in my class marked as #Component? [duplicate] - spring

Question

This question already has answers here:
Why is my Spring #Autowired field null?
(21 answers)
Closed 2 months ago.
I tried different solutions trying to use #Value within a class, even added #Autowire to the constructor, nut the #Value fields will still be null. I understand that this fields are injected after the construction of the object, but for me, their value is null, even if I just added a string, and not a property.
What am I doing wrong? I am using Spring boot 3, but anyway I have Controllers where this works, so probably I am wrong somewhere...
#Slf4j
#Component
public class TokenReceiver {
#Value("openid")
private String scope;
#Value("${spring.security.oauth2.client.registration.keycloak.client-id}")
private String clientId;
#Value("${spring.security.oauth2.client.registration.keycloak.client-secret}")
private String clientSecret;
private String grantType = "password";
#Autowired
private RestTemplate restTemplate;
public String getAccesToken(String username, String password) {
String accessTokenUrl = "https://keycloak.fh-kufstein.ac.at:8443/realms/BigOpenRealm/protocol/openid-connect/token";
LinkedMultiValueMap<String, String> requestParams = new LinkedMultiValueMap<>();
requestParams.add("scope", scope);
requestParams.add("grant_type", grantType);
requestParams.add("client_id", clientId);
requestParams.add("client_secret", clientSecret);
requestParams.add("username", username);
requestParams.add("password", password);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(requestParams, headers);
KeycloakToken keycloakAccessToken = getAccessTokenResponse(request, accessTokenUrl);
return keycloakAccessToken.getAccess_token();
}
and the class from which the method it is called:
#Slf4j
#Component
public class GetProxyStrategy extends AbstractProxyStrategy {
#Autowired
TokenReceiver tokenReceiver;
public GetProxyStrategy() {
super();
}
public GetProxyStrategy(HttpServletRequest httpServletRequest, HttpHeaders headers, RestTemplate restTemplate) {
super(httpServletRequest, headers);
}
private StatusAwareEntityHolder callWebservice(String serviceUrl,
String username, String password)
throws IOException, ProxiedWebServiceExecutionException {
String accessToken = tokenReceiver.getAccesToken(username, password);
both classes are in the packages that are scanned:
#SpringBootApplication(scanBasePackages = {"my.domain.boo.microservice.portal.*"})

Answer 1

Because you create the TokenReceiver object by yourself. In this class Spring has nothing to do - it doesn't interfere. So it doesn't inject anything and doesn't address your #Value or #Component annotation for this object.
Instead you should let spring create the instance for you.
Since you've put the #Component annotation, the chances are that it will be able to create a corresponding bean and put it onto the application context. So you should just inject it:
#Service // should be a bean by itself
public class MyWebServiceCaller {
#Autowired
TokenReceiver tokenReceiver; // <--- Note the injection here!
private StatusAwareEntityHolder callWebservice(String serviceUrl,
String username, String password)
throws IOException, ProxiedWebServiceExecutionException {
String accessToken = tokenReceiver.getAccesToken(username, password);
[...]
}
}